<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>Canvas</title>
</head>
<body>
    <canvas id="simple-square" width="800" height="800"></canvas>
    <script>
        function drawSquare() {
            var canvas = document.getElementById('simple-square');
            if (canvas.getContext) {
                var context = canvas.getContext('2d');
                context.fillStyle = 'rgb(13, 118, 208)';
                context.fillRect(2, 2, 798, 798);
            } else {
                // put code for browsers that don't support canvas here
                alert('This page requires an HTML5 compliant browser to render correctly. Other browsers may not see anything.');
            }
        }

        drawSquare();
    </script>
</body>
</html>